Project Summary This project aims to develop and evaluate a behavioral intervention for adolescent cannabis use disorder that emphasizes adaptive responding to negative affective symptoms (e.g., depression, anxiety). Maladaptive cognitive, behavioral, and emotional reactions to negative affect are associated with substance use and substance use problems (including cannabis). Adolescence and young adulthood represents a developmental period in which the regulation of negative emotions is still being developed, as well as a time when cannabis use is prevalent and cannabis use disorders onset. Thus, developing and evaluating cannabis use disorder interventions that emphasize the improvement of responding to negative affect may be particularly important for this developmental period. First, we will develop an intervention that weaves skills and strategies for responding adaptively to negative affect, particularly as it relates to high-risk times for cannabis craving and use, into an evidence-based substance use disorder intervention for individuals in late adolescence and early adulthood. After developing the initial protocol and delivering it to a small sample of participants, we will gather feedback to guide refinements to the intervention. After refining the intervention, which we plan to be a 12-session individual treatment, we will conduct the pilot randomized clinical trial. Participants (N = 80) aged 18-25 with cannabis use disorder and elevations in constructs representing maladaptive reactivity to negative affect (i.e., high anxiety sensitivity, low distress tolerance, or facets of emotion dysregulation including high emotional suppression and low cognitive reappraisal ability) will be randomized to receive either: (a) standard cognitive behavioral therapy for adolescent substance use disorders (SUD-CBT) or (b) the novel intervention we develop, affective management training for cannabis use disorders (CUD-AMT). Participants will be assessed at baseline, post-treatment, and a 6-month follow-up assessment on self-report and behavioral indices of the targeted mechanisms, as well as on substance use outcomes (both cannabis-specific and substances more broadly defined). A sub-set of participants (n = 50) will also undergo pre- and post-treatment fMRI assessment to evaluate whether neural indices of emotion regulation are improved to a greater extent in CUD-AMT compared to SUD-CBT. Cannabis use disorder is the most prevalent substance use disorder among adolescents and young adults, and often leads to the use of other substances. Negative affect and disorders associated with high negative affect (i.e., anxiety and unipolar mood disorders) are highly prevalent and associated with significant substance use disorder comorbidity. Targeting a process that is still malleable in late adolescence and young adulthood and that is associated with the maintenance of substance use disorders has the potential to reduce the burden of substance use disorders in this population, thus making a significant public health impact.